Coastal Cities Sink Faster Than Seas Rise Due to Land Subsidence

Many coastal cities are sinking at rates double the global sea level rise. Jakarta is sinking about 14mm per year, much faster than the oceans are rising.
By Newsroom | Environment, Urban Planning |

As of May 19, 2026, a new research analysis led by Julius Oelsmann confirms that urban land subsidence is currently the primary driver of relative sea-level rise for many coastal populations. While global sea levels rise at an absolute rate of approximately 3.15mm annually, coastal cities are sinking at rates that frequently double this figure, creating a compounded threat for millions of inhabitants.

Earth's sinking cities: Study reveals the urban areas plummeting toward sea level - leaving millions of residents at risk of being plunged underwater - 1

The velocity of sinking land in key urban centers often eclipses the vertical growth of global oceans, rendering traditional sea-level models insufficient for local risk assessment.

Earth's sinking cities: Study reveals the urban areas plummeting toward sea level - leaving millions of residents at risk of being plunged underwater - 2
CityObserved Annual Subsidence (Approx.)
Jakarta~14mm
Tianjin/Bangkok/Lagos/Alexandria4mm – 13.5mm
Global Urban Average~2mm

Drivers of Urban Compression

The degradation of the Earth's surface beneath these metropolitan hubs is not a singular phenomenon. Investigations identify three primary mechanisms accelerating this decline:

Earth's sinking cities: Study reveals the urban areas plummeting toward sea level - leaving millions of residents at risk of being plunged underwater - 3

  • Groundwater Extraction: The primary catalyst. As cities drain underground aquifers, the structural integrity of the soil fails, leading to permanent land collapse.

  • Urban Loading: The 'sheer weight' of massive infrastructure projects creates downward pressure, compressing sub-surface layers.

  • Sediment Disruption: Human intervention in river deltas restricts the natural replenishment of silt, causing the ground to settle.

Case Studies in Equilibrium and Decline

The geography of risk is asymmetrical. While cities like Jakarta face acute displacement threats, other regions experience the opposite. In Finland and Sweden, geological rebound is actually elevating land faster than the oceans rise, resulting in a relative sea-level drop.

Read More: India and Norway Sign 12 Deals for Green Partnership in Oslo

Earth's sinking cities: Study reveals the urban areas plummeting toward sea level - leaving millions of residents at risk of being plunged underwater - 4

Conversely, Tokyo offers a blueprint for mitigation. By shifting water policy and securing alternative resources to stop aggressive groundwater depletion, the city successfully decelerated its subsidence rate, which had previously spiked beyond 10mm per year.

"Tackling both land subsidence and sea-level rise is key if we want to protect coastal communities," notes the Oelsmann study.

Investigative Context: The Delta Crisis

More than half of the world's river-delta regions are currently sinking. These areas, home to massive agricultural and economic activity, are losing their elevation to a combination of tectonic shifts and anthropogenic water use. Research using satellite radar tracking suggests that even under moderate climate scenarios, the downward movement of the ground will remain the dominant factor in flooding for the next several decades.

Current mitigation efforts, including the work mentioned by the World Economic Forum, suggest that reversing these trends requires deep structural reform in urban water management and industrial policy. The reliance on simple sea-wall construction is increasingly viewed as a temporary aesthetic, rather than a solution to the fundamental collapse of the substrate upon which these cities are built.

Read More: Cities Use New Ways to Stop Sewers Flooding During Heavy Rain

Frequently Asked Questions

Q: Why are coastal cities sinking faster than the sea level is rising?
Research shows that urban land subsidence, where the ground itself sinks, is happening faster than global sea levels are rising. This is mainly caused by too much groundwater being pumped out, the weight of city buildings, and changes to river deltas.
Q: Which cities are most affected by land subsidence?
Cities like Jakarta are sinking very fast, about 14mm per year. Other cities such as Tianjin, Bangkok, Lagos, and Alexandria are also sinking between 4mm and 13.5mm per year.
Q: What causes land subsidence in cities?
The main reasons are cities pumping too much water from underground, the heavy weight of large buildings and infrastructure pressing down on the land, and changes in river deltas that stop natural sediment buildup.
Q: Are there any cities where the land is rising?
Yes, cities in Finland and Sweden are experiencing geological rebound, where the land is actually rising faster than the sea level.
Q: How can cities stop sinking?
Tokyo is an example of a city that slowed its sinking by changing its water policies and finding other water sources to stop over-pumping groundwater. This shows that better water management is key.
Q: What is the main finding of the recent research on urban subsidence?
The research confirms that urban land subsidence is the main reason why sea levels are rising for many people living in coastal areas, and this is a bigger problem than global sea-level rise alone.